TAPPING THE PERICARDIUM IN THE DOG 505 



the tube used for carrying off the fluid, for introducing into the thorax 

 solution of chloride of sodium, - 5 per cent. ; sublimate 1 in 5,000 ; 

 carbolic acid 5 per cent., or thymol solution warmed to 98° Fahr. 

 What success was attained is not recorded. In man, an incision 

 is sometimes made into the upper part of the thorax (thoracotomy), 

 a portion of a rib removed at a lower point, and the sac freely 

 irrigated. Such operations are far less hopeful in our patients, in 

 which treatment is generally a question, not so much of saving life, 

 as of restoring usefulness. Under these circumstances the operation 

 is burdened with conditions which it is unable to satisfy, and which 

 render it difficult to carry out in private practice. The same is 

 largely true of the surgery of the lung, lately introduced in man, 

 which aims at direct operative treatment of diseased processes in 

 the lungs and in other organs of the chest. As a last resort in the 

 treatment of a valuable patient thoracotomy might, however, be 

 tried. 



(2) Tapping the Pericardium in the Dog. — In the dog, tapping 

 the pericardium becomes necessary in the treatment of exudative 

 pericarditis, which occurs in the acute and chronic forms. Attention 

 is always first attracted by the physical symptoms. 



As soon as the pericardium contains a certain quantity of liquid, 

 the heart is thrust upwards and a little forwards, the degree of dis- 

 placement depending on the amount of exudate. The pericardial 

 sac becomes distended, especially about its base, lifting the pulmonary 

 lobes, and pushing them upwards towards the vertebra?, though 

 to a much less degree than in pleurisy. Thus on palpation of the 

 precordial region the heart's impulse appears weak, or seems lost. 

 On auscultation the normal sounds, clearly detected in health even 

 in very small patients, are dull, distant, and smothered, or completely 

 inaudible. When the heart is but slightly compressed the pulse 

 preserves its character ; but as soon as pressure becomes marked 

 the pulse grows small, fugitive, weak, and sometimes almost imper- 

 ceptible. 



Compression of the auricles — the portions of the heart which 

 collapse most readily — impedes the flow of blood, produces cyanosis, 

 venous pulse in the jugulars, and mechanical dyspnoea owing to 

 stasis of blood in the lungs. The symptoms of oppression at first 

 seen are undoubtedly of reflex origin, due to the pain in the inflamed 

 pericardium. 



If not treated, acute pericarditis may rapidly lead to death, 

 sometimes in less than a week. It may also (though exceptionally) 



